Floor underlayment



FIG. 1 is a perspective view of a floor underlayment in accordance withthe present invention;

FIG. 2 is a top plan view of the invention illustrated in FIG. 1;

FIG. 3 is a side elevational view of the invention illustrated in FIG.1; and,

FIG. 4 is a bottom plan view of the invention illustrated in FIG. 1.

The broken lines in the drawings depict features of the floorunderlayment that form no part of the claimed design.

CLAIM The ornamental design for a floor underlayment, as shown anddescribed.